Dexamethasone suppression test in predicting response to tricyclic antidepressants in depressed outpatients.

75 outpatients who presented to an affective disorder clinic received the dexamethasone suppression test (DST). Following 1 week observation, and following 1 week on low-dose imipramine HCl, all patients who remained depressed (Hamilton score 16 or greater) were given a full clinical trial of imipramine HCl (150-300 mg/day) over a minimum 3- to 5-week period. Of the 45 patients who required this trial and who received imipramine HCl for at least 3 weeks, there was no relationship between DST suppression or nonsuppression vs. clinical response to imipramine HCl. There was a statistically significant trend for suppressors (negative DST) to respond either spontaneously or to low-dose imipramine HCl as opposed to nonsuppressors (positive DST).